CSC

    Math & Trig

    Returns the cosecant of an angle (in radians). The cosecant is the reciprocal of sine: 1/SIN(x).

    Translations
    EnglishCSC
    FrenchCSC
    SpanishCSC
    GermanCOSEC
    ItalianCSC
    PortugueseCSC
    DutchCOSEC
    PolishCSC
    RussianCSC
    TurkishCSC
    CzechCOSEC
    HungarianCSC
    SwedishCOSEC
    DanishCOSEC
    FinnishCSC
    Syntax
    CSC(number)

    Arguments

    • numberAn angle in radians for which to find the cosecant.
    Examples
    =CSC(PI()/2)
    1

    Cosecant of 90° equals 1

    =CSC(PI()/6)
    2

    Cosecant of 30° equals 2

    Tips & Best Practices
    • Available since Excel 2013
    • Returns #DIV/0! when SIN(number) is 0 (e.g. 0, π, 2π)
    • Use RADIANS() to convert degrees to radians first
    Common Mistakes
    • Passing an angle where sine equals 0 (like 0, π, or 2π), which returns a #DIV/0! error since cosecant is the reciprocal of sine and undefined wherever sine is 0
    • Passing an angle in degrees directly to CSC without converting it first - CSC expects radians, so CSC(30) doesn't give the cosecant of 30 degrees, and RADIANS(30) needs to be used instead
    • Confusing CSC with COS or assuming it's some kind of alternate cosine function - cosecant is specifically the reciprocal of sine, unrelated to cosine except through the broader trigonometric identities
    Related Functions
    SINCalculates the sine of an angle, the reciprocal relationship to what CSC calculates (CSC(x) = 1/SIN(x)).
    SECCalculates the secant, the reciprocal of cosine, a parallel function to CSC's reciprocal-of-sine relationship.
    RADIANSConverts a degree value into radians, the unit CSC expects for its angle argument.
    Frequently Asked Questions

    Why does CSC return a #DIV/0! error?

    The angle is one where sine equals 0, like 0, π, or 2π - since cosecant is 1/SIN(x), dividing by that zero produces the error.

    Why do I need RADIANS before using CSC?

    CSC expects its input in radians, not degrees. If your angle is in degrees, wrap it in RADIANS first, like CSC(RADIANS(30)).

    Is cosecant related to cosine?

    Not directly - cosecant is the reciprocal of sine specifically. Secant (SEC) is the reciprocal of cosine, a separate but parallel function.

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